按多列分组并在DATATABLE C＃上聚合多个列

Question

我想总结不同产品的qunatites。我是Linq的新手，我无法获得预期的数据。请帮忙。

我的数据表看起来像这样：

Proname | Qty1 | Qty2 | Qty3
----------------------------
A       | 2    | 0    | 4 
A       | 0    | 4    | 5
A       | 3    | 2    | 0
B       | 5    | 4    | 2
C       | 6    | 4    | 3
C       | 1    | 1    | 1



Expected Result :

Proname | Qty1 | Qty2 | Qty3
----------------------------
A       | 5    | 6    | 9 
B       | 5    | 5    | 5
C       | 7    | 5    | 4

Answer 1

这应该让你开始：

var products = new DataTable();
products.Columns.Add("ProductName", typeof(string));
products.Columns.Add("Qty1", typeof(int));
products.Columns.Add("Qty2", typeof(int));
products.Columns.Add("Qty3", typeof(int));

products.Rows.Add(new object[] {"A", 2, 0, 4});
products.Rows.Add(new object[] {"A", 0, 4, 5});
products.Rows.Add(new object[] {"A", 3, 2, 0});
products.Rows.Add(new object[] {"B", 5, 4, 2});
products.Rows.Add(new object[] {"C", 6, 4, 3});
products.Rows.Add(new object[] {"C", 1, 1, 1});

products.AsEnumerable()
        .GroupBy (p => p.Field<string>("ProductName"))
        .Select (p => new {
            Name = p.Key,
            Qty1 = p.Sum (a => a.Field<int>("Qty1")),
            Qty2 = p.Sum (a => a.Field<int>("Qty2")),
            Qty3 = p.Sum (a => a.Field<int>("Qty3"))
        });

输出：

参考：

• LINQ to DataTable
• LINQ query on a DataTable